Frequently, small product items, and in particular pharmaceuticals such as pills, tablets, capsules, caplets, gelcaps, and lozenges, are packaged in blister packs or cards where each pocket of the package holds a single pill. For ease of reference, any of the above and other small items or objects that may be required to be singulated will be referred to, collectively and generically, as “pills.” Blister packs are made by forming a thermoplastic strip formed as an array of upwardly open pockets. A filling machine then puts the desired number of pills (which may be a single pill, more than one pill, or no pill depending on the dosing instructions) into each pocket and a backing to the array of pockets is provided thereby sealing each pill in a pocket separate and apart from other pills within the pack. If more than one pill is to be put into any given pocket, each pill is individually put into the pocket to better control the placement of the pills into the pocket.
In order to make sure that each blister package is marketable, each of the blister pack pockets must contain the desired number of pills or the package is marked as a reject and culled from the product line. The field of pill-dispensing features many different mechanisms that are designed to recognize, sort and count pills of all types and sizes. Many of these devices are unreliable for two basic reasons. Either they fail to singulate pills appropriately and more than the desired number of pills are placed into a single blister pack pocket or they fail to get a pill into the blister pack, leaving the entire pack one pill or more short. Such a failure is expensive when the product itself is expensive or difficult to dispose of, as is the case with many pharmaceuticals. The problem associated with separating pills from each other for individual packaging, or singulation, is exacerbated by the wide variety of different sizes and shapes of different types of pharmaceuticals. If a singulating apparatus has been designed to singulate a particular size and/or shape of pill, such an apparatus may have difficulty singulating pills having different sizes, different shapes, or both. For example, an apparatus that readily singulates capsules may have difficulty singulating tablets. Two tablets may be dispensed, rather than the desired single tablet, because of “shingling” (i.e., two tablets enter the singulating cavity, with one tablet partially on top of another tablet).